[DRBD-user] Delayed replication /w Protocol C?

[Lars Ellenberg]

On Sat, May 09, 2009 at 08:29:22PM -0700, c smith wrote:
> Hi-
> 
> I'm experiencing a strange issue with DRBD not following protocol C and
> replication happening long after local writes are complete. If, for example,
> I've got /dev/drbd0 mounted at /mnt with an ext3 filesystem, `dd
> if=/dev/zero of=/mnt/test.zero bs=1000M count=1` will write the file at
> local speeds and complete long before DRBD replicates any of it (or as far
> as I can see by watching /proc/drbd)  It sometime takes as long as 10s
> before there is any activity in /proc/drbd.

man fsync

> My aim is to map DRBD resources to LVs. I have done some testing using both
> LVs and physical partitions as DRBD resources' devices and have found the
> same results.  I'm using 8.3.1 compiled against 2.6.27.21-0.1-xen on
> OpenSUSE 11.1.  From what I can tell there must be something  else on a
> higher level messing with replication but I can't for the life of me think
> of what it might be.

page cache


-- 
: Lars Ellenberg                
: LINBIT HA-Solutions GmbH
: DRBD®/HA support and consulting    http://www.linbit.com

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